root-ansh

private val saveFileToSystemSAF: ActivityResultLauncher<String> = registerForActivityResult(CreateDocument(mimeType = "*/*")) { result -> // or mimeType = "application/pdf" / "image/*" 
        val uri = result
        val file = state.fileToBeSaved // the file/bitmap that needs to be writteen to user selected uri
        val context = this
        if (uri!=null && file!=null){
            lifecycleScope.launch {
                context.saveFileToUserSelectedPath(uri,file) // writing file to user selected uri
                Snackbar
                    .make(binding.root,"Saved file :${file.name} to user selected directory", Snackbar.LENGTH_SHORT) 
                    .setAction("show"){context.openSystemViewerForSAFUri(uri)} //check next section for info on this

root-ansh

data class FileInfo(
    val nameWithExtension: String,
    val extension: String?,
    val mimeType: String?,
    val size: Long?,
    val sizeFormatted: String?,
    val createdOn: Long?,
    val modifiedOn: Long?,
    val originalLocationPath: String?
){

root-ansh

// converts any uri(content/file) to a local temp file first in cache directory for easy read/write
suspend fun Uri.toLocalFile(context: Context,localFileLocation:File = context.cacheDir): File? {
    val uri = this
    return withContext(Dispatchers.IO) {
        try {
            val fileInfo = FileInfo.fromSAFUri(context,uri)
            val fileName = fileInfo?.nameWithExtension?: "${System.currentTimeMillis()}.bin"
            val tempFile = File(localFileLocation, fileName)
            context.contentResolver.openInputStream(uri)?.use { inputStream ->
                FileOutputStream(tempFile).use { outputStream ->

root-ansh

val intent = Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
  type = "image/*" //"application/pdf" // "*/*"
  putExtra(Intent.EXTRA_MIME_TYPES, arrayOf("image/*")) // required in some android versions. also good if you set type as */* and want to filter mimetypes
  addCategory(Intent.CATEGORY_OPENABLE)
  addFlags(Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION or Intent.FLAG_GRANT_READ_URI_PERMISSION)// optional for our app, but required if you intend to save the  SAF content uris(temporary by nature) in databases
}
getFileFromSystem.launch(intent)

root-ansh

    private val getFileFromSystem: ActivityResultLauncher<Intent> = registerForActivityResult(StartActivityForResult()) { result ->
        if (result.resultCode == RESULT_OK) {
            val uri = result.data?.data
            lifecycleScope.launch {
                val file = uri?.toLocalFile(this@XMLActivity) // convert to local file
                updateUi()// handle local file
            }

        }

root-ansh

import android.view.View
import androidx.core.widget.NestedScrollView
import timber.log.Timber

/**
 * when a recycler view can be in nested scroll view, its ability to recycle views is lost as its
 * linear layout manager loads all the views at one go. and since all views are loaded at once,
 * the layout manager or (recycelr view) don't fire the last child callbacks properly.
 *
 * For pagination, the basic principle is:

root-ansh

apply plugin: "io.gitlab.arturbosch.detekt"               // detekt STEP1 applying plugin (detekt = kotlin code's static analyser)
apply plugin: "checkstyle"                                // checkstyle STEP1 applying plugin (checkstyle = java code's static analyser)

// detekt STEP2 plugin configuration
detekt {
    parallel = true   
    allRules = true                
    ignoreFailures = true                 
    debug = true     
}

root-ansh

# .github/workflows/basic.yaml
      - name: CodeAnalysis via  detekt
        run: ./gradlew detekt

      - name: Upload detekt results
        uses: actions/upload-artifact@v2
        with:
          name: detekt_results
          path:app/build/reports/detekt
            

root-ansh

// app/build.gradle
plugins {
    ...
}

android {

   ...

    defaultConfig {

root-ansh

(A little complex article, but works very fine after installing LA of LAMP : https://www.digitalocean.com/community/tutorials/how-to-install-linux-apache-mysql-php-lamp-stack-ubuntu-18-04)
(Easier article : https://www.tecmint.com/install-lamp-with-phpmyadmin-in-ubuntu-18-04/)

Setting up the L:Linux

we are assuming you are on a linux machine. Although it would be good,if you have an ssh with you and have set up the machine to act as server with one of the firewalls.
More details Here

Setting up the A: Apache